Three-dimensional computed tomographic evaluation of morphologic airway changes after mandibular setback osteotomy for prognathism

摘要: Abstract Objective. To observe changes in the pharyngeal airway and hyoid bone position after mandibular setback osteotomy 30 patients with prognathism by means of 3-dimensional computed tomography (3DCT). Study design. Preoperative postoperative (CT) examinations were performed on 17 treated sagittal split ramus rigid osteosynthesis 13 intraoral vertical without osteosynthesis. The amount was measured preoperative to difference axial CT images. sizes evaluated from semitransparent crosscut 3DCT Postoperative displacement a technique superimpose hard tissue image image. helical scan used examination. volume rendering create Results. mean 7.8 ± 2.1 mm range 5 11 mm. Three months surgery, lateral frontal widths had decreased significantly comparison width. reduction rates width 23.6% 11.4%, respectively. diminished did not recover either 6 or 1 year surgery most cases. Downward posterior seen postoperatively. There positive correlations between (r = 0.54) 0.42). no significant differences two surgical techniques. Conclusion. Three-dimensional practical imaging evaluate morphologic changes. may have irreversible narrowing surgery. (Oral Surg Oral Med Pathol Radiol Endod 2000;89:278-87)